Relay with passive springs



Feb. 13, 1951 K. w GRAYBILL ETAL 2,541,355

RELAY WITH PASSIVE SPRINGS Filed Feb. 12, 1947 Fla;

' I INVENTORS. KENNETH w. GRAYBILL FI HANS sENGEBuscH 1 ATTORNEY Patented Feb. 13, 1951 UNITED STATES PATENT OFFICE RELAY WITH PASSIVE SPRINGS Kenneth W. Graybill, Elmhurst, and Hans Sengebusch, Villa Park, Ill., assignors to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application February 12, 1947, Serial No.'728,128

'3 Claims. 1

The present invention relates to electromagnetic relays of the multiple contact type and more particularly to the mechanical construc tion thereof. In the embodiment herein described the movable springs as well as the stationary springs are passive, only one spring, that is the armature restoring spring, is tensioned in the ordinary meaning of the term.

One of the objects of the'present invention is to provide a relay wherein any one of the stationary or movable springs may be removed and replaced without disturbing any other spring.

Another object of the invention is to provide a relay wherein the springs are kept in alignment at the mounting, plate end and also at'the operating end.

Another object is to provide a relay in which the spacing between the movable and stationary springs is determined by notches in insulating combs, one comb for this purpose serves as the spool head at the mounting end and another notched comb being mounted at the opposite or operating end of the core and a third comb, parallel to the first two, being fixed between the armature and the armature restoring spring,

Another object of this invention is to provide a relay in which adjustments of contact springs have been eliminatedentirely or at least reduced to a minimum, there being only two principal adjustments, tensioning of the main or armature restoring spring and the armature back stop.

Still another object of this invention is to so arrange the notched insulating comb at the mounting end, that any notch may be occupied by a make, a break or amovable spring.

Other objects and advantages in connection with this invention will be apparent from the explanations which follow, when reviewed with the accompanying drawing, consisting of eight figures.

Figure 1 is a side view of one embodiment of the relay showing the spring combination on the left side.

Figure 2 is a bottom view of a relay showing the armature, the armature mounting spring and the off-set section of the movable springs, to provide clearance for the up and down movement of these springs without interference with the stationary springs.

Figure 3 is an end view taken from the right of Figure 2 looking toward the operating or contact end of the relay showing, in particular, the notched comb which is-movable'with-the armature and which carries with 'it, the movable springs.

Figure 4 shows the outline of a movable spring, indicating the off-set feature.

Figure 5 shows an outline of a stationary spring indicating the off-set feature.

Figure 6 is a side view of a spring assembly to show the approximate relative position of the two stationary combs, the movable comb and the metal contacts, by which arrangement the burnishing action is accomplished.

Figure 7 is a top view of a pair of springs, that is one movable and one stationary spring.

Figure 8 is a view of a part of a spring pile-up to show the ease with which any spring may be replaced without disturbing any other spring.

Figure 1 is a plan view of the left side of one embodiment of the present invention showing six springs assembled in six of the twelve available notches in the stationary comb 6! and the movable comb 62. Although many combinations are possible, the three springs in each set shown are arranged as break-make combinations. The middle spring of each set shown is firmly gripped in the armature comb 62 and therefore will move up and down when the armature moves in response to the energization and de-energization of the coil.

It is-to be noted in Figure 1 that all movable and all stationary springs are gripped in comb 84 at the mounting end of the core and are also gripped in one of the combs Si or G2 at the contact end, that is, the stationary springs are associated with the stationary comb 6i and the movable springs are associated with the movable armature comb 62. This method of assembling both the stationary and movable springs in prepared notches in insulators of said spring assembly, provides an accurate and pro-determined position for the respective springs. There is no tension in any of these contact springs, in the ordinary meaning of the term and all springs are kept in alignment by this unique mounting method. The necessary spring pressure for maintaining the normally closed contacts and for restoring the armature, when the coil is de-energized, is maintained by adjusting the main or armature restoring spring 2. This armature restoring spring being the only spring which is tensioned, thus spring adjustment is almost completely eliminated. This restoring spring 2 exerts its pressure against a notched comb 62, in the notches of which the movable springs, such as 4|, are tightly embraced and thereforemove with the'comb. This point Where the comb notch grips the movable springs is approximately two and one-half inches from the point where the springs are held rigidly in the mounting plate assembly and approximately one-quarter inch from the metal contact. This point of pressure for the movable springs will be mentioned later in connection with the description of the fulcrum for the up and down movement of a portion of the length of the stationary springs.

It should be noted at this point, by reference to Figure 8, that after removing the two screws II, the plate l2 can be taken off, as well as the insulator l3, after which any one of the springs may be removed. By this unique construction the spring combination in any pile-up can be altered at will or any spring can be removed and. replaced by a new one, in the event of damage from any cause whatsoever. This feature will be referred to again in connection with the description of Figure 8.

It will be noted that the spacing of the contact ends of the springs is determined by notches in the supporting combs, therefore a Wide range of spacing is available to meet all conditions of contact requirements in the various combinations of break, make, make and break, break and make, etc. The terminals 4 and 5 are rigidly fixed in comb 84, for the termination of the ends of the coil windings as well as the external wires, not shown, of the circuit over which the coil would be energized.

In Figure 2 it will be noted that the armature 2| extends, not only the full length of the coil core, not shown, but some distance beyond and that the core is equipped with two pole pieces 80 in Figure 3 and 6 in Figure l, of magnetic material. At the mounting end of the core, the armature 2| is equipped with a T-shaped spring member 22 with two lugs projecting beyond the end of the armature where they fit into grooves in non-magnetic brackets 23 and 24, causing a surface contact to be maintained be tween armature 2| and pole piece 80, seen in Figure 8. The spring member 22 maintains slight tension on the armature 2| in a direction away from the coil core. The armature back stop 1 limits the down movement, or restoring move-- ment of the armature 2| and the air gap 3 between the armature 2| and the magnetic pole piece 6 can be adjusted by bending the end 8 of the armature back stop I. A brass or other non-magnetic residual, not shown, is fitted over the surface of one edge of the magnetic pole piece 6 adjacent the armature, which performs the usual function of preventing the armature 2| from sticking to the core end after the coil is de energized.

It will be seen in Figure 2 and in Figure '7 that the special design of the movable springs, for ex-- ample spring 4|, that is providing an off-set por tion 43, allows free movement up and down of the movable springs without interference with the comb bl, which is rigidly attached to the coil core (not shown). The break and make springs are tightly embraced in comb 84. As shown in this Figure 2, facilities are provided for mounting spring sets on opposite sides of the relay, the armature 2| being located on the third side and the armature restoring spring 2 on the fourth side.

Figure 3 is an end view of the relay showing the relative positions of the combs 6|, 62 and 84. The notches for the springs are of uniform spacing and therefore maintain all springs in correct relation with each other without pro-tensioning in the ordinary meaning of the term. The notches in the combs are so arranged that either a movable or a stationary spring may occupy any spring position. This feature allows a great variety of contact combinations to be assembled while using a single type of comb arrangement and also it provides for alterations to be made at any time, with ease and dispatch.

Figures 4 and 5 show the outline of the movable and stationary springs respectively. Particular attention is directed to the cut-away portions 42 and 52, forming shoulders which fit over one edge of insulator 82 and the inside edge of the notches, such as notches 83 to prevent any end to end movement of the springs after being assembled in the spring pile-up. The movable springs are usually equipped ,with two precious metal contacts, not shown. The stationary springs 5| are split for a short distance from the free end and one metal contact is provided on each leg thus formed.

In Figure 6 attention is directed to the relation between the movement of the metal contacts of the movable springs 4| and the metal contacts of the stationary springs 5| and which causes rubbing action, to burnish the contact metal, when the relay is energized or de-energized. When the armature 2| moves in response to the energization of the coil, the insulator 62, which represents a part of the armature comb 62, also moves and carries upwards the movable spring 4|. It will be remembered that spring 4|, due to its off-set portion, bypasses the fixed insulatcr BI and therefore as this spring 4| is moved by insulator 552, spring 4| will bend at the point 15 on line 68. As a result the metal contact on spring 4| subscribes an are 12 with point 15 as its center, that is, an arc with a radius of approximately two and three-quarter inches, which is the distance between the vertical lines and 68. However, one of the notches in insulator 62 will be the point where power is applied to move spring 4| and this point is approximately one-quarter inch from the metal contact on spring 4| and when the contact on spring 4| meets the contact on spring 5|, spring 5| is carried to a higher level and spring 5| bends on a line 61, at the point 14, where it is tightly embraced in a notch in insulator 5 I, which as previously explained, is fixed. Thus, point 14 at the edge of insulator 6| becomes a fulcrum over which spring 5| bends. The are 13 subscribed by the metal contact of spring 5| is therefore centered at point 14 which is approximate- 1y three-quarter inch from the contact on spring 5|. The rubbing of the two metal contacts of springs 4| and 5|, moving on widely different arcs, results in the burnishing of the contacts.

Figure 7 is an outline of one movable and one stationary spring, approximately as seen from the bottom of Figure 6. This view shows more clearly the off-set portion 43 of spring 4|, indicating the clearance between spring 4| and the edge of comb 6|, to provide unhampered. movement of spring 4| when the comb 62 moves up or down.

Figure 8 is an exploded view of a part of a spring assembly to illustrate the ease with which a spring or springs may be removed or replaced Without disturbing an other spring. Item represents the magnetic pole piece which fits snugly on the coil core, not shown, and adjacent to the insulating comb member 84, which is also fitted to the core and slightly larger than element 80. The non-magnetic member 24 is first assembled on top of element 89 followed by the insulating member 82 with its unnotched edge resting againstinsulator 84 and with its screw holes 85 lined up with the threaded holes 81 in the magnetic pole piece-80. The top face of the insulator 82 is slightly above the bottom edge of the notches 89 in insulating member 84 and the notches 89 in 84 are lined up with the notches 83. These two insulating members, 82 and 84, form the support or assembly base upon which the movable and stationary springs are mounted. The shoulders at the two edges of the notched portion, such as 52 of the spring fit into the notches on the left edge of insulator 82 and against its right edge which prevents any end to end movement. After the springs have been assembled in their respective slots, insulator I3 is placed on top and finally the clamping plate I2 and two screws ll. These screws I i pass through holes in plate I2, insulators l3 and 82 and nonmagnetic element 24 and into the threaded holes 8| in the magnet core end. In order to remove one or more springs for repair, replacement or changing the circuit, it is only necessary to remove the two screws l I, also remove plate 12 and insulator l3, leaving the top edge of each spring in the pile-up exposed and the spring free to be removed. It should be noted here that the design of the relay is such that two separate spring pile-ups can be assembled on each relay, that is one spring pile-up referred to as being above the coil and one pile-up below the coil or, one pile-up on the left side and one on the right side, depending upon the position in which the relay is mounted on the supporting frame, not shown.

Attention is directed to a small projection 54 shown in Figure 8 on one edge of spring 5IA and to a hole 13A in the insulator I3. In a second embodiment of this invention all springs would be equipped with this projection 54 on the oppo- Site edge of the spring from the cut-out portion 52. The insulator 13 would be equipped with one hole, such as I3A, for each spring in the pile-up. The feature of ease-of-replacement of any spring is maintained in this embodiment.

Having described the invention, what is considered to be novel and desired to have protected by Letters Patent will be pointed out in the appended claims.

What is claimed is:

1. In a circuit controlling device, a first fixed insulator, parallel slots in said first insulator, a plurality of fiat stationary and movable contact springs, the base ends of said stationar and movable contact springs inserted in said slots and their fiat surfaces arranged in superimposed relation in a single alined and superimposed pile-up, a second fixed insulator spaced a predetermined distance from said first insulator, corresponding parallel slots in said second insulator in which only the stationary contact springs at a point near their free ends are inserted for positioning the free ends of said stationary contact springs, a coil core and coil positioned between said first and second insulators, said coil core being substantially in axial alinement with said contact springs, a movable third insulator spaced near said second insulator, corresponding parallel slots in said third insulator in which Only the movable contact springs at a point near their free ends are inserted for normally positioning the free ends of said movable contact springs and for operating said movable contact springs to engage 6 saidstatlonary springs in response to the actua tion of said movable insulator, an armature and opposed fiat armature return spring separated by said third insulator, and a single insulating plate positioned over the slots in said first insulator for maintaining said stationary and movable contact springs in their respective slots,said plate being removable to permit removal and replacement of any one of said contact springs without disturbing any of the remaining contact springs.

2. In a circuit controlling device as claimed in claim 1 including a curved portion on each of said movable contact springs for by-passing said second insulator to prevent said fixed second insulator from interfering with the movement of said movable contact springs.

3. In a relay, a core, a coil winding on said core, a first and a second insulating spool head attached to the ends of said core for confining said winding, a plurality of stationary and movable contact springs, a plurality of slots in the first of said spool heads in which the base ends of said stationary and movable contact springs are assembled for arranging said contact springs in superimposed relation with each other in a superimposed contact spring pile-up, a plurality of slots in the second of said spool heads in which the free ends of said stationary contact springs are assembled for maintaining said stationary contact springs in their assembled positions, an insulator, a plurality of slots in said insulator in which the free ends of said movable contact springs are assembled for maintaining said movable contact springs in their assembled positions, an insulating plate mounted over said slots and contact springs in said first spool head to retain said contact springs assembled in said slots, said plate being removable to permit removal and replacement of any of said contact springs without disturbing any of the remaining contact springs, an armature for moving said insulator to move said movable contact springs to engage and disengage said stationary contact springs, and an armature return spring on the opposite side of said coil winding from said armature, said spring and said armature being separated by said insulator.

KENNETH W. GRAYBILL. HANS SENGEBUSCH.

REFERENCES CITED The following references are of record in the file of this patent:

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